I’ve been able to log in and authenticate my account in my application, but when I try to use any GET api with the same access token, it gives me a 401 Authorization Required error.
I’m using the Let’s Tweet with Unity plug-in, but modifying for new APIs.

And the signature base string:
GET&https%3A%2F%2Fapi.twitter.com%2F1.1%2Fstatuses%2Fhome_timeline.json&count%3D20%26oauth_consumer_key%3DFDa3tzC0KRM5jgbu4AxtUMtzk%26oauth_nonce%3DTEBGWVb5LrGgdnc3nmrrgy3fIMBetCMv%26oauth_signature_method%3DHMAC-SHA1%26oauth_timestamp%3D1425949307%26oauth_token%3D85978870-OLj22ve1zbMMSho8CirG0g97QGWhefEizUs0z8mhp%26oauth_version%3D1.0